1. Field of the Invention
An aspect of the present invention relates to a computer system allowing to configure a partition, and may be applied to a crossbar module for transmitting information with packets by interconnecting system board modules.
2. Description of the Related Art
In a large-scale server system, resources of one server computer, such as CPUs or memories, may be divided into a plurality of groups (hereinafter referred to as partitions). Each of the partitions can independently activate or deactivate its system, and is regarded as one totally independent server machine which can operate its corresponding system. To simultaneously transmit, or broadcast in other words, information within each partition, its simultaneous transmission range is only partition-wide, and one partition does not exert an influence on an operation of another partition.
Especially, there are cases where a plurality of system board modules (i.e., one type of system expansion unit modules each equipped with a CPU, a memory, and so forth; hereinafter abbreviated to SBs) are respectively divided into a plurality of partitions, crossbar module units (hereinafter abbreviated to XB units) respectively interconnect and manage some of the system board modules, and packets are broadcast. In these cases, the XB units are interconnected via bus devices. Each of the partitions may belong to a single XB unit, and sometimes may belong to a plurality of XB units. Therefore, if a partition extends across a plurality of XB units, information must be broadcast to the partition using an inter-XB-unit bus device. However, it is normally difficult to secure an inter-XB unit bus device as a resource for each partition due to bottlenecks in terms of cost, etc. Accordingly, there arises the need for a technique for identifying and controlling partitions in conflict when using an inter-XB-unit bus device.
Conventionally, the conflict priorities of all of partitions (uniquely determined by a system configuration) that may use the above described inter-XB-unit bus device are fixedly controlled (i.e., fixed conflict priority method).
With the above described fixed conflict priority method according to conventional technology, a partition that does not use an inter-XB-unit bus device is also involved in calculating the conflict priorities. This leads to a problem such that the use rate of inter-XB-unit bus devices falls. There has been also the demand for a technique able to implement a system that saves the cost of inter-XB-unit bus devices by eliminating the need for securing an inter-XB-unit bus device as a resource for each partition, and does not reduce the performance extremely.